rc.initdiskless revision 145693
1#!/bin/sh 2# 3# Copyright (c) 1999 Matt Dillon 4# All rights reserved. 5# 6# Redistribution and use in source and binary forms, with or without 7# modification, are permitted provided that the following conditions 8# are met: 9# 1. Redistributions of source code must retain the above copyright 10# notice, this list of conditions and the following disclaimer. 11# 2. Redistributions in binary form must reproduce the above copyright 12# notice, this list of conditions and the following disclaimer in the 13# documentation and/or other materials provided with the distribution. 14# 15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25# SUCH DAMAGE. 26# 27# $FreeBSD: head/etc/rc.initdiskless 145693 2005-04-29 23:02:56Z brooks $ 28 29# On entry to this script the entire system consists of a read-only root 30# mounted via NFS. The kernel has run BOOTP and configured an interface 31# (otherwise it would not have been able to mount the NFS root!) 32# 33# We use the contents of /conf to create and populate memory filesystems 34# that are mounted on top of this root to implement the writable 35# (and host-specific) parts of the root filesystem, and other volatile 36# filesystems. 37# 38# The hierarchy in /conf has the form /conf/T/M/ where M are directories 39# for which memory filesystems will be created and filled, 40# and T is one of the "template" directories below: 41# 42# base universal base, typically a replica of the original root; 43# default secondary universal base, typically overriding some 44# of the files in the original root; 45# ${ipba} where ${ipba} is the assigned broadcast IP address 46# ${class} where ${class} is a list of directories supplied by 47# bootp/dhcp through the T134 option. 48# ${ipba} and ${class} are typicall used to configure features 49# for group of diskless clients, or even individual features; 50# ${ip} where ${ip} is the machine's assigned IP address, typically 51# used to set host-specific features; 52# 53# Template directories are scanned in the order they are listed above, 54# with each sucessive directory overriding (merged into) the previous one; 55# non-existing directories are ignored. 56# 57# The existence of a directory /conf/T/M causes this script to create a 58# memory filesystem mounted as /M on the client. 59# 60# Some files in /conf have special meaning, namely: 61# 62# Filename Action 63# ---------------------------------------------------------------- 64# /conf/T/M/remount 65# The contents of the file is a mount command. E.g. if 66# /conf/1.2.3.4/foo/remount contains "mount -o ro /dev/ad0s3", 67# then /dev/ad0s3 will be be mounted on /conf/1.2.3.4/foo/ 68# 69# /conf/T/M/diskless_remount 70# The contents of the file points to an NFS filesystem. E.g. if 71# /conf/base/etc/diskless_remount contains "foo.com:/etc", 72# then foo.com:/etc will be be mounted on /conf/base/etc/ 73# If the file contains a pathname starting with "/", then 74# the root path is prepended to it; this allows relocation of 75# the root filesystem withouth changing configuration files. 76# 77# /conf/T/M/md_size 78# The contents of the file specifies the size of the memory 79# filesystem to be created, in 512 byte blocks. 80# The default size is 10240 blocks (5MB). E.g. if 81# /conf/base/etc/md_size contains "30000" then a 15MB MFS 82# will be created. In case of multiple entries for the same 83# directory M, the last one in the scanning order is used. 84# NOTE: If you only need to create a memory filesystem but not 85# initialize it from a template, it is preferrable to specify 86# it in fstab e.g. as "md /tmp mfs -s=30m,rw 0 0" 87# 88# /conf/T/SUBDIR.cpio.gz 89# The file is cpio'd into /SUBDIR (and a memory filesystem is 90# created for /SUBDIR if necessary). The presence of this file 91# prevents the copy from /conf/T/SUBDIR/ 92# 93# /conf/T/SUBDIR.remove 94# The list of paths contained in the file are rm -rf'd 95# relative to /SUBDIR. 96# 97# You will almost universally want to create the following files under /conf 98# 99# File Content 100# ---------------------------- ------------------------------------------ 101# /conf/base/etc/md_size size of /etc filesystem 102# /conf/base/diskless_remount "/etc" 103# /conf/default/etc/rc.conf generic diskless config parameters 104# /conf/default/etc/fstab generic diskless fstab e.g. like this 105# 106# foo:/root_part / nfs ro 0 0 107# foo:/usr_part /usr nfs ro 0 0 108# foo:/home_part /home nfs rw 0 0 109# md /tmp mfs -s=30m,rw 0 0 110# md /var mfs -s=30m,rw 0 0 111# proc /proc procfs rw 0 0 112# 113# plus, possibly, overrides for password files etc. 114# 115# NOTE! /var, /tmp, and /dev will be typically created elsewhere, e.g. 116# as entries in the fstab as above. 117# Those filesystems should not be specified in /conf. 118# 119# (end of documentation, now get to the real code) 120 121dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` 122 123# chkerr: 124# 125# Routine to check for error 126# 127# checks error code and drops into shell on failure. 128# if shell exits, terminates script as well as /etc/rc. 129# 130chkerr() { 131 case $1 in 132 0) 133 ;; 134 *) 135 echo "$2 failed: dropping into /bin/sh" 136 /bin/sh 137 # RESUME 138 ;; 139 esac 140} 141 142# Create a generic memory disk 143# 144mount_md() { 145 /sbin/mdmfs -i 4096 -s $1 -M md $2 146} 147 148# Create the memory filesystem if it has not already been created 149# 150create_md() { 151 if [ "x`eval echo \\$md_created_$1`" = "x" ]; then 152 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then 153 md_size=10240 154 else 155 md_size=`eval echo \\$md_size_$1` 156 fi 157 mount_md $md_size /$1 158 /bin/chmod 755 /$1 159 eval md_created_$1=created 160 fi 161} 162 163# DEBUGGING 164# 165# set -v 166 167# Figure out our interface and IP. 168# 169bootp_ifc="" 170bootp_ipa="" 171bootp_ipbca="" 172if [ ${dlv:=0} -ne 0 ] ; then 173 iflist=`ifconfig -l` 174 for i in ${iflist} ; do 175 set -- `ifconfig ${i}` 176 while [ $# -ge 1 ] ; do 177 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then 178 bootp_ifc=${i} ; bootp_ipa=${2} ; shift 179 fi 180 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then 181 bootp_ipbca=$2; shift 182 fi 183 shift 184 done 185 if [ "${bootp_ifc}" != "" ] ; then 186 break 187 fi 188 done 189 # Insert the directories passed with the T134 bootp cookie 190 # in the list of paths used for templates. 191 i="`/sbin/sysctl -n kern.bootp_cookie`" 192 [ "${i}" != "" ] && bootp_ipbca="${bootp_ipbca} ${i}" 193 194 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}" 195fi 196 197# Figure out our NFS root path 198# 199set -- `mount -t nfs` 200while [ $# -ge 1 ] ; do 201 if [ "$2" = "on" -a "$3" = "/" ]; then 202 nfsroot="$1" 203 break 204 fi 205 shift 206done 207 208# The list of directories with template files 209templates="base default ${bootp_ipbca} ${bootp_ipa}" 210 211# The list of filesystems to umount after the copy 212to_umount="" 213 214# If /conf/diskless_remount exists, remount all of /conf. This allows 215# multiple roots to share the same conf files. 216if [ -d /conf -a -f /conf/diskless_remount ]; then 217 nfspt=`/bin/cat /conf/diskless_remount` 218 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 219 nfspt="${nfsroot}${nfspt}" 220 fi 221 mount_nfs $nfspt /conf 222 chkerr $? "mount_nfs $nfspt /conf" 223 to_umount="/conf" 224fi 225 226# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, 227# and /conf/${bootp_ipa}. For each subdirectory found within these 228# directories: 229# 230# - calculate memory filesystem sizes. If the subdirectory (prior to 231# NFS remounting) contains the file 'md_size', the contents specified 232# in 512 byte sectors will be used to size the memory filesystem. Otherwise 233# 8192 sectors (4MB) is used. 234# 235# - handle NFS remounts. If the subdirectory contains the file 236# diskless_remount, the contents of the file is NFS mounted over 237# the directory. For example /conf/base/etc/diskless_remount 238# might contain 'myserver:/etc'. NFS remounts allow you to avoid 239# having to dup your system directories in /conf. Your server must 240# be sure to export those filesystems -alldirs, however. 241# If the diskless_remount file contains a string beginning with a 242# '/' it is assumed that the local nfsroot should be prepended to 243# it before attemping to the remount. This allows the root to be 244# relocated without needing to change the remount files. 245# 246for i in ${templates} ; do 247 for j in /conf/$i/* ; do 248 # memory filesystem size specification 249 # 250 subdir=${j##*/} 251 if [ -d $j -a -f $j/md_size ]; then 252 eval md_size_$subdir=`cat $j/md_size` 253 fi 254 255 # remount 256 # 257 if [ -d $j -a -f $j/remount ]; then 258 nfspt=`/bin/cat $j/remount` 259 $nfspt $j 260 chkerr $? "$nfspt $j" 261 to_umount="${to_umount} $j" # XXX hope it is really a mount! 262 fi 263 264 # NFS remount 265 # 266 if [ -d $j -a -f $j/diskless_remount ]; then 267 nfspt=`/bin/cat $j/diskless_remount` 268 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then 269 nfspt="${nfsroot}${nfspt}" 270 fi 271 mount_nfs $nfspt $j 272 chkerr $? "mount_nfs $nfspt $j" 273 to_umount="${to_umount} $j" 274 fi 275 done 276done 277 278# - Create all required MFS filesystems and populate them from 279# our templates. Support both a direct template and a dir.cpio.gz 280# archive. Support dir.remove files containing a list of relative 281# paths to remove. 282# 283# The dir.cpio.gz form is there to make the copy process more efficient, 284# so if the cpio archive is present, it prevents the files from dir/ 285# from being copied. 286 287for i in ${templates} ; do 288 for j in /conf/$i/* ; do 289 subdir=${j##*/} 290 if [ -d $j -a ! -f $j.cpio.gz ]; then 291 create_md $subdir 292 cp -Rp $j/* /$subdir 293 fi 294 done 295 for j in /conf/$i/*.cpio.gz ; do 296 subdir=${j%*.cpio.gz} 297 subdir=${subdir##*/} 298 if [ -f $j ]; then 299 create_md $subdir 300 echo "Loading /$subdir from cpio archive $j" 301 (cd / ; /rescue/pax -x cpio -r -z -p e -f $j) 302 fi 303 done 304 for j in /conf/$i/*.remove ; do 305 subdir=${j%*.remove} 306 subdir=${subdir##*/} 307 if [ -f $j ]; then 308 # doubly sure it is a memory disk before rm -rf'ing 309 create_md $subdir 310 (cd /$subdir; rm -rf `/bin/cat $j`) 311 fi 312 done 313done 314 315# umount partitions used to fill the memory filesystems 316[ -n "${to_umount}" ] && umount $to_umount 317